Re: [PATCH V1 06/16] xen/ioreq: Make x86's hvm_ioreq_(page/vcpu/server) structs common

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 14/09/2020 16:16, Jan Beulich wrote:
> On 10.09.2020 22:22, Oleksandr Tyshchenko wrote:
> > --- a/xen/include/xen/ioreq.h
> > +++ b/xen/include/xen/ioreq.h
> > @@ -23,6 +23,40 @@
> >   
> >   #include <asm/hvm/ioreq.h>
> >   
> > +struct hvm_ioreq_page {
> > +    gfn_t gfn;
> > +    struct page_info *page;
> > +    void *va;
> > +};
> > +
> > +struct hvm_ioreq_vcpu {
> > +    struct list_head list_entry;
> > +    struct vcpu      *vcpu;
> > +    evtchn_port_t    ioreq_evtchn;
> > +    bool             pending;
> > +};
> > +
> > +#define NR_IO_RANGE_TYPES (XEN_DMOP_IO_RANGE_PCI + 1)
> > +#define MAX_NR_IO_RANGES  256
> > +
> > +struct hvm_ioreq_server {
> > +    struct domain          *target, *emulator;
> > +
> > +    /* Lock to serialize toolstack modifications */
> > +    spinlock_t             lock;
> > +
> > +    struct hvm_ioreq_page  ioreq;
> > +    struct list_head       ioreq_vcpu_list;
> > +    struct hvm_ioreq_page  bufioreq;
> > +
> > +    /* Lock to serialize access to buffered ioreq ring */
> > +    spinlock_t             bufioreq_lock;
> > +    evtchn_port_t          bufioreq_evtchn;
> > +    struct rangeset        *range[NR_IO_RANGE_TYPES];
> > +    bool                   enabled;
> > +    uint8_t                bufioreq_handling;
> > +};
> Besides there again being the question of hvm_ prefixes here,
> is the bufioreq concept something Arm is meaning to make use
> of? If not, this may want to become conditional ...
Yes, I would like to make use of it to optimize virtio notifications as 
we don't need to wait for them to be processed by the IOREQ server.
Cheers,

--
Julien Grall